Improvement of InGaN-GaN light-emitting diodes with surface-textured indium-tin-oxide transparent ohmic contacts

This paper presents a surface-textured indium-tin-oxide (ITO) transparent Ohmic contact layer on p-GaN to increase the optical output of nitride-based light-emitting diodes (LED) without destroying the p-GaN. The surface-textured ITO layer was prepared by lithography and dry etching, and dimensions of the regular pattern were approximately 3 x 3 mum. The operating voltage of the surface-textured LED was almost the same as that of the typical planar LED since the ITO layer was in Ohmic contact with the p-GaN. The experimental results indicate that the surface-textured ITO layer is suitable for fabricating high-brightness GaN-based light emitting devices.